Piperacillin/tazobactam-induced sudden severe thrombocytopenia in a patient with a pressure ulcer: a case report.

The standard treatment for an infected pressure ulcer (PU) with osteomyelitis is debridement, wound coverage and antibiotic administration. However, systemic administration of antibiotics in patients with osteomyelitis is controversial, and the optimal treatment duration for chronic osteomyelitis has not been standardised. We report a case of sudden severe thrombocytopenia induced by piperacillin/tazobactam (PIPC/TAZ) in a patient with PU-related osteomyelitis. A 57-year-old male patient with paraplegia, using a wheelchair full-time, presented to our plastic surgery department with infection of a stage IV hard-to-heal ischial PU. We surgically debrided the necrotising tissue and raised an ipsilateral biceps femoris musculocutaneous propeller flap for wound coverage. Polymicrobial infections, including Pseudomonas aeruginosa, were detected in the bone biopsy sample; therefore, systemic PIPC/TAZ was administered for the osteomyelitis. Unexpectedly, during the next 12 days of antibiotic administration, the patient's platelet count acutely dropped to 1×103/µl over three days. Based on a series of examinations, PIPC/TAZ was suspected to be the most likely cause of the severe thrombocytopenia. After drug discontinuation, the thrombocytopenia gradually improved. PIPC/TAZ is one of the most widely used antibiotic combinations in the plastic surgery field; it is conventionally administered for hard-to-heal wounds such as PUs and diabetic foot. The present case suggests that surgeons must take special precautions for patients undergoing PIPC/TAZ treatment. In this report, PIPC/TAZ-induced thrombocytopenia and the efficacy of antibiotic treatment for PU-related osteomyelitis are discussed in light of the available literature.

Drug-induced thrombocytopenia in children.

BACKGROUND: Acute, immune-mediated thrombocytopenia may be caused by many different approved drugs as well as by other substances including vaccines, complementary and alternative medicines, herbal remedies, nutritional supplements, foods and beverages. All causes are described as drug-induced thrombocytopenia (DITP). Often the cause is not recognized, resulting in recurrent thrombocytopenia and inappropriate treatments. Systematic analysis of children (age less than 18 years) with suspected DITP has not been previously reported. PROCEDURES: (1) We searched 15 databases to identify articles describing children with thrombocytopenia as an adverse effect of drugs and other substances. Articles were reviewed to assign levels of evidence for an association of the suspected substance with thrombocytopenia. (2) Data from the BloodCenter of Wisconsin were reviewed to identify reports of drug-dependent, platelet-reactive antibodies in children with suspected DITP. RESULTS: Of 2,191 articles identified, 242 were selected for review. Seventy-two articles reporting 74 individual patients and nine groups of patients had evaluable data. Eleven individual patients and one group had definite evidence and 40 patients and three groups had probable evidence for an association of the suspected substance with thrombocytopenia. Thirty-two substances had a definite or probable association with thrombocytopenia. During 2008-2012, sera from 91 children with suspected DITP were tested and 21 had drug-dependent, platelet-reactive antibodies involving six substances. CONCLUSIONS: Drugs and other substances must be considered as potential causes of thrombocytopenia. Evidence from published reports and data for drug-dependent, platelet-reactive antibodies can help clinicians evaluate of children with unexpected thrombocytopenia.

Beyond the Norm: A Case of Multiorgan Injury Triggered by Ibuprofen.

We report the case of a 71-year-old African American male with a history of chronic obstructive pulmonary disease (COPD), heart failure, vitiligo, penicillin allergy, and cocaine use, who presented with respiratory symptoms and was diagnosed with sepsis, COVID-19 pneumonia, exacerbation of COPD, and acute kidney injury (AKI). Treatment included antibiotics and high-dose steroids. The patient developed thrombocytopenia, autoimmune hemolytic anemia, acute liver failure, and interstitial nephritis associated with prolonged ibuprofen use. High-dose steroids and ibuprofen discontinuation led to significant improvement. This case highlights the rare occurrence of multiorgan injury from ibuprofen use, possibly aggravated by COVID-19, emphasizing the need for cautious non-steroidal anti-inflammatory drug (NSAID) use and close patient monitoring.

A Rare Case of Vancomycin-Induced Immune Thrombocytopenia.

Vancomycin-induced immune thrombocytopenia (ITP) is a rare type of drug-induced immune thrombocytopenia (DITP) that can lead to life-threatening consequences as a result of its use. We herein report a case of a 74-year-old male with a history of diabetes mellitus type II, Alzheimer's disease, and stroke who presented to the ICU with sepsis. The patient was on heparin for 20 days prior to presentation, with platelet levels at the time within normal limits as per his baseline. Following the introduction of vancomycin to his clinical regimen in the treatment of sepsis, the patient developed a significant drop in platelet count from 400 x10³/mm³ to 70 x10³/mm³. Discontinuation of the drug leads to improvement of the platelet counts confirming the diagnosis of vancomycin-induced ITP.

Drug-induced thrombocytopenia associated with trastuzumab in a patient with HER2-positive recurrent gastric cancer.

Here, we report a 57-year-old female patient with HER2-positive recurrent gastric cancer who experienced drug-induced thrombocytopenia associated with trastuzumab, a humanized anti-HER2 monoclonal antibody. Shortly after the initiation of S-1, oxaliplatin, and trastuzumab chemotherapy, the patient experienced severe thrombocytopenia and did not respond to platelet transfusions. Based on the findings of increased numbers of polynuclear megakaryocytes in the bone marrow and an elevated level of platelet-associated IgG (PA-IgG), the patient was diagnosed with drug-induced thrombocytopenia (DITP). The platelet count recovered rapidly with oral prednisolone (1 mg/kg). Since we initially suspected oxaliplatin as the causal agent, S-1 was restarted as a monotherapy, followed by trastuzumab after a 3-week interval, without oxaliplatin. On the second day after the addition of trastuzumab, severe thrombocytopenia occurred again, which suggests that trastuzumab was responsible for the DITP. The patient no longer experienced severe thrombocytopenia during the subsequent S-1 and oxaliplatin chemotherapy, which supports this hypothesis.

Amiodarone-Induced Immune Thrombocytopenia: A Rare Hematologic Side Effect of a Common Cardiac Drug.

Thrombocytopenia is a rare immune-mediated hematologic complication of amiodarone. We describe a case of delayed-onset amiodarone-induced thrombocytopenia in a 72-year-old male and highlight the process of working it up. A timely diagnosis of drug-induced immune thrombocytopenia is crucial in order to minimize unnecessary testing, avoid treatments with potential harm, and prevent life-threatening hemorrhagic complications.

A rare case of absolute thrombocytopaenia in a COVID-19 patient: Case report.

INTRODUCTION: Thrombocytopaenia, one of the most common haematological disorders worldwide, is characterised by platelet counts <150,000/mm3. Patients with coronavirus disease (COVID-19) were found to commonly exhibit haematological abnormalities, often with mild forms of thrombocytopaenia. Absolute thrombocytopaenia tends to be rare among these patients and is believed to be secondary to immune-induced thrombocytopaenia. CASE PRESENTATION: A 53-y-old man presented with fever and generalised body ache that persisted for a few days. His polymerase chain reaction test was positive for COVID-19, for which he was treated with acetaminophen, levofloxacin, and favipiravir. On the third day of treatment, he noticed bruising and bleeding, mainly in the oral cavity, with clot formation. A complete blood picture (CBP) revealed severe thrombocytopaenia with an almost-zero count. Prednisone 1 mg/kg/d and frequent doses of intravenous platelet transfusion were administered as rescue therapy to prevent fatal bleeding. The patient was able to recover. CLINICAL DISCUSSION: Immune thrombocytopaenia should be considered in patients presenting with bleeding tendencies after severe acute respiratory syndrome coronavirus 2 infection. Serial CBP is recommended for vulnerable patients, especially during the second and third weeks of hospitalisation, for the early detection and prevention of life-threatening COVID-19 complications. CONCLUSIONS: Absolute thrombocytopaenia is a rare condition. Such a condition should be considered in patients presenting with bleeding tendencies with severe Covid-19 infection. With early diagnosis and appropriate treatment, patients' lives can be saved.

[Letter to the Editor] Incorrect assignment of affected nucleotides in footprinting/probing experiments.

Address correspondence to Sergey Belikov or Lars Wieslander, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden. E-mail: sergey.belikov@su.se or lars.wieslander@su.se.

Novel Random Mutagenesis Method for Directed Evolution.

Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

Oxaliplatin hypersensitivity: evaluation, implications of skin testing, and desensitization.

BACKGROUND: Oxaliplatin hypersensitivity (OXS) presents a challenge in the treatment of oxaliplatin-sensitive malignancies. OBJECTIVE: To analyze patient characteristics of patients with OXS, skin test results, and desensitization outcomes to optimize management. METHODS: Over 5 years, 48 patients with OXS were referred to the allergy/immunology unit at Massachusetts General Hospital. Their clinical reaction patterns were analyzed. Immediate hypersensitivity skin testing was used for risk stratification, and drug desensitizations were performed by using 3 related continuous intravenous protocols that were chosen based on clinical history, skin test reactivity, and the patients' previous desensitization outcomes. RESULTS: OXS occurred in both sexes, with mostly gastrointestinal-related tumors. Hypersensitivity reaction (HSR) onset had occurred during any course of therapy (course nos. 1-28), with a median onset at course no. 8. HSR to oxaliplatin was similar to those observed with cisplatin and carboplatin, including cutaneous, cardiovascular, pulmonary, and gastrointestinal symptoms. However, neurologic symptoms, including tingling, and systemic symptoms, including fever and chills, occurred more often in patients with OXS. Unique to OXS, 2 patients developed drug-induced thrombocytopenia; 1 patients also developed drug-induced hemolytic anemia. Skin testing was positive for the majority of patients with OXS (27/46 [59%]) and correlated with a greater likelihood of developing an HSR during subsequent desensitizations. We safely performed 200 desensitizations in 48 patients with OXS. CONCLUSION: OXS is common with much similarity to other platin agents but also have distinct differences in the onset of hypersensitivity, sex, tumor type, drug-induced hemolytic anemia, and drug-induced thrombocytopenia. Skin testing was helpful for risk stratification. All of the desensitizations were completed successfully.

Polishing the craft of genetic diversity creation in directed evolution.

Genetic diversity creation is a core technology in directed evolution where a high quality mutant library is crucial to its success. Owing to its importance, the technology in genetic diversity creation has seen rapid development over the years and its application has diversified into other fields of scientific research. The advances in molecular cloning and mutagenesis since 2008 were reviewed. Specifically, new cloning techniques were classified based on their principles of complementary overhangs, homologous sequences, overlapping PCR and megaprimers and the advantages, drawbacks and performances of these methods were highlighted. New mutagenesis methods developed for random mutagenesis, focused mutagenesis and DNA recombination were surveyed. The technical requirements of these methods and the mutational spectra were compared and discussed with references to commonly used techniques. The trends of mutant library preparation were summarised. Challenges in genetic diversity creation were discussed with emphases on creating "smart" libraries, controlling the mutagenesis spectrum and specific challenges in each group of mutagenesis methods. An outline of the wider applications of genetic diversity creation includes genome engineering, viral evolution, metagenomics and a study of protein functions. The review ends with an outlook for genetic diversity creation and the prospective developments that can have future impact in this field.